Program Dr_IDXs_SEACLID
  ! Calculating PDSI, SPI, SPEI 
  use netcdf

!------------------------------------------------------------------------------

  Real, parameter    :: amssng = -99., Miss=amssng
  Integer, Parameter :: NMonth = 12, Nmon=NMonth
  Integer, Parameter :: NVar = 2, Nreg = 7, Nmem = 7, Nlead = 6
  Integer, Parameter :: Ncase = 4       !  obs,mod,cli,ann
  Integer, Parameter :: Ncase_1 = 2     ! obs, ens
  Character (Len=3), Parameter :: Case_1(Ncase_1)=(/"obs","ens"/)
  Character (Len=3), Parameter :: Cases(Ncase)=(/"obs","mod","cli","ann"/)
  !Character (Len=3), Parameter :: Cases(Ncase)=(/"obs","cli","ann"/)

  Integer, Allocatable :: Len_SPI(:)
  Real, Allocatable    :: DatBL(:,:), DatTMP(:,:), Rain(:) ! For calculating SPI, SPEI

  Real, Allocatable    :: beta_spi(:), gamm(:), pzero(:), SPI(:,:,:), SPE(:,:,:)
  Real, Allocatable :: Regs(:,:), Lon(:), Lat(:), xlon(:), xlat(:) 
  Real, Allocatable :: Pr_All(:,:,:,:,:,:,:), T2_All(:,:,:,:,:,:,:)   ! Nlon,Nlat,Nmem,Nlead,Ntime,Ncase,Nmodel
  Real, Allocatable :: xmem(:), xlead(:), xtime(:)
  Real, Allocatable :: SPEI_All(:,:,:,:,:,:)                  ! Nlon,Nlat,Nmem,Ntime,Ncase,Nlen

!------------------------------------------------------------------------------
  ! Ensemble:
  Real, Allocatable :: Pr_ens  (:,:,:,:,:), T2_ens(:,:,:,:,:)       ! Nlon,Nlat,Nlead,Ntime,Ncase_1
  Real, Allocatable :: SPEI_ens(:,:,:,:,:)                          ! Nlon,Nlat,Ntime,Ncase_1,Nlen

  ! Notes:
  ! 1) Dat_Mon(ivar,ist,iyr,imw), where ivar=1:Temp (F), ivar=2:Rainfall (inch); ist=1..Nst; iyr=YBas1..YBas2; imw=1..Nmon (or Nweek) 
  !    Dat_Mon used to calculating PDSI
  ! 2) Temp_Inp (Temp in C deg), Rain_Inp (Rainfall in mm/month) (1:Nlon1,1:Nlat1,1:Ntime), Ntime=(YBas2-YBas1+1)*Nmon
  !    Temp_Inp and Rain_Inp to be used to write out as input data
  ! 3) Prec (mm/month), Temp (C) (1:Ntime,1:Nst)
  ! 4) DatBL (mm/month), DatTMP (C) (1:Ntime,1:Nst): Used to calculating SPI, SPEI

!------------------------------------------------------------------------------
  Character (Len=255) :: Fname, BL_Dir, R_Fname, T_Fname, Out_Dr_Fname
  Character (Len=255) :: Inp_Dir, Out_Dir, Mask_File
  Character (Len=3)   :: TVar, RVar
  Character (Len=10),Allocatable :: Model_nm(:)
  Logical :: status, Empty

  Integer :: Yr1, Yr2, Nmodel, NYear, maxyrs
  Integer :: NLen, Nst, Nlon, Nlat, IO, Ntime, Nt, it, Landpoint
  Integer :: imod, ist, iyr, imw, ivar, isys, system, ilon, ilat
  Integer :: Nt1

!------------------------------------------------------------------------------
! For writing to NC file:
  Real, allocatable, Dimension (:,:,:,:) :: X4d
  Real, allocatable, Dimension (:) :: X1d,Xt
!------------------------------------------------------------------------------

  Namelist /File_Dir_Names/ Inp_Dir, Model_nm, Mask_File, Out_Dir, TVar, RVar
  Namelist /Data_Info/      Yr1, Yr2, Nmodel, NLen
  Namelist /Model_name/     Model_nm
  Namelist /Dr_Timescale/   Len_SPI
!------------------------------------------------------------------------------

  Open (1, file="Namelist_Dr_Reg.txt", Status="Old")     ! Tinh voi APH 1961-2015

  Read (1, File_Dir_Names)
  Read (1, Data_Info)
  Allocate (Len_SPI(NLen)); Allocate (Model_nm(Nmodel))
  Read (1, Model_name)
  Read (1, Dr_Timescale)
  Close (1)

  Nyear = (Yr2 - Yr1 + 1); Ntime = Nyear*NMonth; maxyrs = NYear
  Nt = Ntime - Nmon   ! Tru SL nam cuoi cung (vi chi co cac thang du bao ung voi cac LT)
  Call Read_Regs 
  print*,"Parameters: Nlat,Nlon,Nst,Nlen,Ntime=",Nlat,Nlon,Nst,Nlen,Ntime

  Call Read_all_data
  Call Do_Ensemble
  !stop
  ! T2_ens(:,:,:,:,:)       ! Nlon,Nlat,Nlead,Ntime,Ncase_1
  !Do imod=1,Nmodel
     Call Reinit
     !Call Read_all_data (Model_nm(imod))
     print*,"Reading data done ..."
     !------------------------------------------------------------------------------
     print*,"Beginning: Ntime, Nst=",Ntime, Nst
     print*,"Parameters: Nlat,Nlon,Nst,Nlen,Ntime=",Nlat,Nlon,Nst,Nlen,Ntime

     ! For calculating SPI, SPEI:
      SPEI_ens=Miss
      Ntime1=Ntime           !!!!!!!!!!
      Do ilead=1,Nlead
         Nt1 = Nt + ilead
         Do icas=1,Ncase_1
            ist=0; DatBL=Miss; DatTMP=Miss; Ntime=Ntime1
            Do ilon=1,Nlon
               Do ilat=1,Nlat
                  if (Regs(ilon,ilat)>0) then
                     ist=ist+1;
                     !DatBL (1:Ntime,ist) = Pr_All(ilon,ilat,imem,ilead,1:Ntime,icas,imod) !Rain_Inp(ilon,ilat,1:Ntime)
                     !DatTMP(1:Ntime,ist) = T2_All(ilon,ilat,imem,ilead,1:Ntime,icas,imod) !Temp_Inp(ilon,ilat,1:Ntime)
                     DatBL (1:Ntime,ist) = Pr_ens(ilon,ilat,ilead,1:Ntime,icas)
                     DatTMP(1:Ntime,ist) = T2_ens(ilon,ilat,ilead,1:Ntime,icas)
                     Lat(ist)=xlat(ilat)
                  endif
               Enddo
            Enddo
!pause
            Ntime=Nt1
            if (Allocated(SPI)) Deallocate (SPI); Allocate (SPI(Nst,Ntime,NLen))
            SPI(:,:,:) = amssng
            Call Cal_SPEI
            !Call Cal_SPI

            !if (icas==1.AND.imem==3) then; print*,SPI,"LT=",ilead; pause; endif
            ist=0
            Do ilon=1,Nlon
               Do ilat=1,Nlat
                  if (Regs(ilon,ilat)>0) then
                     ist=ist+1
                     Do ilen=1,Nlen
                        SPEI_ens(ilon,ilat,1:Ntime,icas,ilen)=SPI(ist,1:Ntime,ilen)
                     Enddo
                     !X1d(1:Ntime)=SPI(ist,1:Ntime,1); Nt1=Length_series (X1d,Ntime,Miss); print"(A,8I6)","ilead,imem,icas: ",ilead,imem,icas,Nt1
                  endif
               Enddo
            Enddo
!pause
         Enddo
         Ntime=Ntime1
         write (Fname,"(A,I1,A)") trim(Out_Dir)//"SPEI_ens_lead_",ilead,".nc"
         Call Write_Dr_IDXs_to_file (Fname,ilead) !,Model_nm(imod)) 
      Enddo
   !Enddo
   CONTAINS
   !------------------------------------------------------------------------------
   Subroutine Reinit
      if (Allocated(T2_All)) Deallocate (T2_All)
      if (Allocated(Pr_All)) Deallocate (Pr_All)

      if (Allocated (Rain))     Deallocate (Rain)
      if (Allocated (DatBL))    Deallocate (DatBL)
      if (Allocated (DatTMP))   Deallocate (DatTMP)
      if (Allocated (beta_spi)) Deallocate (beta_spi)
      if (Allocated (gamm))     Deallocate (gamm)
      if (Allocated (pzero))    Deallocate (pzero)
      if (Allocated (SPEI_ens)) Deallocate (SPEI_ens)
      if (Allocated (Lat))      Deallocate (Lat)
      if (Allocated (X1d))      Deallocate (X1d)

      Allocate (Rain(Ntime),DatBL(Ntime,Nst),DatTMP(Ntime,Nst))
      Allocate (beta_spi(Nmonth), gamm(Nmonth), pzero(Nmonth))
      !Allocate (SPI(Nst,Ntime,NLen), SPE(Nst,Ntime,NLen))
      !Allocate (SPEI_All(Nlon,Nlat,Nmem,Ntime,Ncase,Nlen))
      Allocate (SPEI_ens(Nlon,Nlat,Ntime,Ncase_1,Nlen))                          ! Nlon,Nlat,Ntime,Ncase_1,Nlen
      Allocate (Lat(Nst),X1d(Ntime))
   End Subroutine Reinit
   !------------------------------------------------------------------------------
   Subroutine Write_Dr_IDXs_to_file (Fname,ilead) !,Model_nm)
     Character (Len=*) :: Fname !,Model_nm
     Character (Len=250) :: t_unit, Var_nm, Var_ln, var_unit, lon_nm, lat_nm, z_nm, t_nm
     Integer :: it, imem, ilead, ireg, icas, ilen, imod
     Real :: zlev(Nlen)

     t_unit="months since 1983-01-01 "; var_unit="-";
     lon_nm="lon"; lat_nm="lat"; z_nm="timescale"; t_nm="time"
     Do ilen=1,Nlen; zlev(ilen)=Len_SPI(ilen);  Enddo
     Allocate (X4d(Nlon,Nlat,Nlen,Ntime))
     ! SPEI_ens(Nlon,Nlat,Ntime,Ncase_1,Nlen)
     Do icas=1,Ncase_1
        Do ilen=1,Nlen 
           Do ilon=1,Nlon
              Do ilat=1,Nlat
                 Do it=1,Ntime
                    X4d(ilon,ilat,ilen,it)=SPEI_ens(ilon,ilat,it,icas,ilen)
                 Enddo
              Enddo
           Enddo
        Enddo
        
        write(Var_ln,"(A,I2.2,A,I1)") "SPEI for "//trim(Case_1(icas))//" with timescale in z=1,2,3 corresponding to 1,3,6 month(s) for Leadtime=",ilead
        write(Var_nm,"(A,I2.2)") trim(Case_1(icas)) !//"_",Len_SPI(ilen)
        if (icas==1) then
           Call wr_ncdf_4d (Fname, xlon,xlat,zlev,xtime, Nlon,Nlat,Nlen,Ntime,X4d,Var_nm, &
                              t_unit,Var_ln,var_unit,lon_nm, lat_nm, z_nm, t_nm,Miss)
        else
           Call wr_ncdf_4d_apd (Fname,X4d,Var_nm,Nlon,Nlat,Nlen,Ntime, &
                              Var_ln,var_unit,lon_nm, lat_nm, z_nm, t_nm,Miss)
        endif
     Enddo
     Deallocate (X4d)
   End Subroutine Write_Dr_IDXs_to_file
   !------------------------------------------------------------------------------
   Integer Function Length_series (X,Ninp,Miss)
     Integer :: Ninp,i,j
     Real :: X(Ninp), Miss

     j=0
     Do i=1,Ninp !,1,-1
        if (X(i)/=Miss) then
           j=j+1
        else
           exit
        endif
     Enddo
     !print*,Ninp,j
     Length_series=j !Ninp-j
   End Function Length_series
   !------------------------------------------------------------------------------
   Subroutine Read_Regs 
     Integer :: ilon,ilat, ireg, ic,j
     Real :: tmp

     Call rd_ncdf_2d (Mask_File,xlon,xlat,Nlon,Nlat,Regs,"reg")
     Nst=0;
     Do ilon=1,Nlon
        Do ilat=1,Nlat
           if (Int(Regs(ilon,ilat))>0) then
              Nst=Nst+1
           endif
        Enddo
     Enddo
     !print*,"Nst=",Nst; pause
   End Subroutine Read_Regs
   !------------------------------------------------------------------------------
   Subroutine Read_all_data ! (Model_nm)
      !Character (Len=*) :: Model_nm
      Integer :: imod,ist,ilon,ilat,ilead,Nlo,Nla,Nme,Nt,icas, it1, it2
      Character (Len=255) :: Fname
      Real, Allocatable :: X4d(:,:,:,:), time(:), xlon(:),xlat(:),xmem(:) !,xtime(:)

      it1=Nmon+1      ! Tinh tu   1/1983
      it2=it1+Ntime-1 ! Tinh den 12/2021
      if (Allocated(X4d))  Deallocate (X4d);  if (Allocated(xmem))  Deallocate (xmem)
      if (Allocated(xlon)) Deallocate (xlon); if (Allocated(xlat))  Deallocate (xlat)
      if (Allocated(time)) Deallocate (time); if (Allocated(xtime)) Deallocate (xtime)
      Do imod=1,Nmodel
         Do ilead=1,Nlead
            write (Fname,"(A,I2.2,A)") trim(Inp_Dir)//trim(TVar)//"_"//trim(Model_nm(imod))//"_lead_",ilead,".nc"
            print*,"Reading ",trim(Fname)
            Do icas=1,Ncase
               Call rd_ncdf_4d (Fname,xlon,xlat,xmem,xtime,Nlo,Nla,Nme,Nt,X4d,trim(Cases(icas)))
               print*,"Nlo,Nla,Nmem,Ntime=",Nlo,Nla,Nme,Nt
               if (imod==1.AND.icas==1.AND.ilead==1) then 
                  Allocate (T2_All(Nlon,Nlat,Nmem,Nlead,Ntime,Ncase,Nmodel),time(Ntime)); 
                  T2_All=Miss; time(1:Ntime)=xtime(1:Ntime)    ! Luu lai de write out
               endif
               Do imem=1,Nmem
                  Do it=1,Ntime
                     T2_All(:,:,imem,ilead,it,icas,imod)=X4d(:,:,imem,Nmon+it)  ! Luu vao T2_All voi time tu Nmon+1 = it1 (Tinh tu   1/1983)
                  Enddo
               Enddo
               Deallocate (xlon,xlat,xmem,xtime,X4d)
            Enddo
            write (Fname,"(A,I2.2,A)") trim(Inp_Dir)//trim(RVar)//"_"//trim(Model_nm(imod))//"_lead_",ilead,".nc"
            Do icas=1,Ncase
               Call rd_ncdf_4d (Fname,xlon,xlat,xmem,xtime,Nlo,Nla,Nme,Nt,X4d,trim(Cases(icas)))
               print*,"Nlo,Nla,Nmem,Ntime=",Nlo,Nla,Nme,Nt
               if (imod==1.AND.icas==1.AND.ilead==1) then; Allocate (Pr_All(Nlon,Nlat,Nmem,Nlead,Ntime,Ncase,Nmodel)); Pr_All=Miss; endif
               Do imem=1,Nmem
                  Do it=1,Ntime
                     Pr_All(:,:,imem,ilead,it,icas,imod)=X4d(:,:,imem,Nmon+it)   ! Luu vao Pr_All voi time tu Nmon+1 = it1 (Tinh tu   1/1983)
                  Enddo
               Enddo
               Deallocate (xlon,xlat,xmem,xtime,X4d)
            Enddo
            Print*,"Reading data ...LT=",ilead
         Enddo
      Enddo
      Print*,"Nt=",Nt
      if (Allocated(xtime)) Deallocate (xtime) 
      Allocate (xtime(Ntime))
      !pause;print*,time
      xtime(:)=time(:)   ! restore xtime
      Deallocate (time)
      Print*,"Reading data ... Done"
   End Subroutine Read_all_data
   !------------------------------------------------------------------------------
   Subroutine Do_Ensemble
      Integer :: ilon,ilat,it,ilead,imem,icas, i,j,k, N
      Real, Allocatable :: X1d(:),Y1d(:)
      Real :: temp,rain
      ! Pr_ens(:,:,:,:,:), T2_ens(:,:,:,:,:)       ! Nlon,Nlat,Nlead,Ntime,Ncase_1
      ! Pr_All(Nlon,Nlat,Nmem,Nlead,Ntime,Ncase,Nmodel)

      N = Nmodel*Nmem*(Ncase-1)
      Allocate (X1d(N),Y1d(N))
      Allocate (T2_ens(Nlon,Nlat,Nlead,Ntime,Ncase_1),Pr_ens(Nlon,Nlat,Nlead,Ntime,Ncase_1))
      T2_ens=Miss; Pr_ens=Miss
      Do ilead=1,Nlead
         Do it=1,Ntime
            T2_ens(:,:,ilead,it,1)=T2_All(:,:,1,ilead,it,1,1)
            Pr_ens(:,:,ilead,it,1)=Pr_All(:,:,1,ilead,it,1,1)
         Enddo
      Enddo
      Do ilon=1,Nlon
         Do ilat=1,Nlat
         if (Int(Regs(ilon,ilat))>0) then
            Do ilead=1,Nlead
               Do it=1,Ntime
                  i=0
                  Do imod=1,Nmodel
                     Do imem=1,Nmem
                        Do icas=3,Ncase   ! "mod","cli","ann"
                           i=i+1
                           X1d(i)=T2_All(ilon,ilat,imem,ilead,it,icas,imod)
                           Y1d(i)=Pr_All(ilon,ilat,imem,ilead,it,icas,imod)
!print*,i,X1d(i),Y1d(i)
                        Enddo
                     Enddo
                  Enddo
                  temp=percentile (X1d,i,0.5,Miss); rain=percentile (Y1d,i,0.5,Miss)
                  T2_ens(ilon,ilat,ilead,it,2)=temp
                  Pr_ens(ilon,ilat,ilead,it,2)=rain
!print*,i,temp,rain
               Enddo
            Enddo
         endif
         Enddo
      Enddo
   End Subroutine Do_Ensemble
   !------------------------------------------------------------------------------
   Include "/home/tanpv/Mylibs/sub_wr_ncdf_Tan.F90"
   Include "/home/tanpv/Mylibs/sub_rd_ncdf_Tan.F90"

   Include "/home/tanpv/Mylibs/Sub_SPI.f90"  ! Chuong trinh tinh chi so han SPI
   Include "/home/tanpv/Mylibs/Sub_SPEI.f90" ! Chuong trinh tinh chi so han SPEI
   Include "/home/tanpv/Mylibs/Sub_Percentile.f90"
   !--------------------------------------------------------------------
   END ! Program
